Grow more crops at the same time

At Aarhus University scientists are currently trying to optimize the cultivation of organic vegetables – to the benefit of both vegetable producers and the environment. An example of this is the recently concluded CORE Organic project “InterVeg” where scientists from the Department of Food Science, together with international colleagues, examined the opportunities of reducing nitrogen loss by growing catch crops together with vegetables such as leek and cauliflower.

“Traditionally, catch crops are sown once the main crop has been harvested. Instead, we examined whether it was possible to grow the two crop types at the same time – in separated rows – and the results seem promising,” says project participant Hanne Lakkenborg Kristensen, Science Leader at Department of Food Science at Aarhus University.

“Growing more crops at the same time does not ensure higher yields, but the major advantage is that Isatis tinctoria excellently complement leek growth, both over and below the soil surface, as they have a deeper root system reaching as deep as two meters. This means that Isatis tinctoria plants are able to grow in – and absorb nitrogen from – soil layers that leeks are unable to reach. These plants not only help reduce leaching; they are also able to store nitrogen for next year’s crops when they are plowed into the soil after the winter, and this reduces the need for additional fertilizer from other sources,” says Hanne Lakkenborg Kristensen.